There isn't sub-resources 'os-flavor-rxtx' under 'flavors', this patch
removed it. And also use all_extensions api sample instead of only flavor
enabled api sample files, because the nova v2.1 API must enable all
the extensions.
Change-Id: I98da27dd616fe829e9f1d8e9ad6cb58eb5660597
Closes-Bug: #1506281